Telephone system



May 17 1927. 1 629099 c. B. FowLER TELEPHONE SYSTEM Filed Aug. 12. 1925 i 2 sheets-sheet 1 l1,62 ,0 May 17'1927 I c.B.vFowL.ER 9 99 TELE PHONE SYSTEM Filed Aug. 12. 1925 v shuts-shut 2 lll lamented May l?, i927;

onirans'rarns l itinerari PATENT oFFIcE.,

CLARENCE FGWLER, OF QUEENS, NEW YORK, ASSIGNR T WESTERN ELE(IVlltlCl COMFANY, NCORFORAIED, F NEW YORK, N; Y., A CORPORATION OF NEW YRK.

TELEPHGNE SYSTEM.

Application filed August 12, 1925. Serial No. 49,742.

',lhis invention relates to telephone systems and more particularly to in'iprovements in the means tor ,interconnecting incoming and outgoing lines at an exchangeln telephone systems including trunk lines or cord circuits iorthe completion ot connections, a trunk liuc, outgoing from a tandem ol'l'ice or trom an A operators positioinv may be selected by an fr operator 'tor 'the extension ol a connection to a B opcratoa position at a distant exchange. Uu the cngagementot' such trunks, the B oporators telephone set may be automatically connected to the incoming ends of engjaged trunks in numerical sequence rather tion iu the order in which they become cugfguged. its the telephone set becomes conncctcd to an engaged trunk and the B operator rei-circs the ninnber ot the rWanted sidiscribor, she inserts the plug oli the Corresponding trunk into the jack ot the Wanted sul iribers line. ln systems oi? this type, the tip and ring conductors at the in coming end of the trunks are usually connect il to ground and battery respectively and when this end ot' a trunk is connected with n sjubscriliiers line, cl'ianges take place in the circuit arrangements of the trunks to 'rz noter the tip and ring cizonductors from said ground and liattery connections to corresponding ground and battery connections ou the tip and ring conductors ot the sub- :scribcrs lineA hdinarily it is essential that this train 4For ahould be done Without inter ruitiou or break in the electrical circuit trom the battery and `round tl'nough these conductorsj as; at the origiiiating otlice the trunk n: 'v be connected in various manners nel? ltnown in the art to maintain through this; electrical circuit certain circuit connections essential 'tor the maintenance of the i-f.,;\.ucz tion 'from the cn lling subscribers line.

if: an' object ot' this invention to provide improrci'l means applicable to systems of the allure und sii ,i typen Ator intniringr that 'thetraiis'tcr olf the battery and ground con inaction-i from n trunli: to a connected line lattea place without intcrruptiim in the con iiuuity oi iiow ol current through `the tip ring` coruluctors ot the trunk.

y tems heretofore ln'orided, it the operator macro; the plug ol n trunl,r intera line i *lowly or only partially, it might hap" Vi: n that the circuit thrimgh the sleeve terminals oli the plug and jack wil be comlil,

:trom the callin()l subscribers line.

pleted prior to the connection `between the respectivetip and ring` terminals thereof to cause circuit changes to take placet-hat Wouldremoye the battery and ground connectionsV trom the tip and ring conductorsot the trunk before these conductors are connected through tothe subscribers line and thus cause a momentary break in the continuity of the electricalcircuit through the trunk conductors. Y y

'Vl`lier`eiore, to attain the aboverand other objects et the intention as will hereina'tter appear, there is provided in accordance with one AFeature of the invention, means whereby even though the sleeve circuit may be `connectcd through prior to the tip and ring connections on the insertion of a plug into a jack, fthe battery and ground transfer does not taire place untilatter the tip and ringconnections have been made and battery and ground have actually been found present on the connected line-V in the accompanying drawings7 Fig. l, shows lthe incoming end of a trunk circuit terminating at a B operators position and a, portion ot a Sequence circuit whereby the Bwoperators telephone set may be con-- nected to engaged trunks in succession and 'also' the outgoing'end of a trunk or subscriberls line whereby a call incoming over the trunk may-be extended beyond, While Fig. .2 shows a B operators telephone set and a circuit arrangement for associating it with lthe sequence circuit.

'lo make clear the functions of the invention as applied to a trunking arrangement ot this type, a'detail description will be made et' a connection lestablished over the trunk to subscribefs line G from a distant otlice (not chown) at which the outgoing end of the trunk terminates and where the connection is completed in any well .known manner l`n this descril'nnon it will be pointed out; besides, how the battery and ground connections are transferred; how the B operators tele-` phone set 100 is automatically connected to engaged trunks in the order in which they are numbered or arranged in the sequence circuit l0 and in particular the connection of the telephone set to trunk 5. It will also be pointed outhow a peg-count meter lOl is operated to regieter the engagement of trunk at the time the operators telephone set is releaiszed :trom said engaged trunk; such re llt lease taking place when plug 11 of trunk 5 (i. lt should be understood that this invention is not limited in its application to this particular typeof system but may equally well be applied to other systems such as plug-ending cord circuits with which an operators telephone set may beautoinatically or manually associated.

Assuming then that a connection is desired over trunk 5 and that an A operator at the distant end of this trunk has caused the tip and ring conductor thereof to be connected together in the usual manner to signal the B oaerator that a connection is desired, the to lowing circuit would be completed: Battery, lower outer armature and back contact of relay 15, Vlower winding ot relay 10, ring conductor ottrunk 5 over the loop at an A operators position to the tip conductor of trunk 5 through the upper winding of relay and upper inner armature and back contact ot relay 15 to ground. This causes the operation ot relay 16 which in operating closes an obvious circuit tor relay 17 and also closes a circuittor the lighting of the guard lamp 18 as follows: Battery, lamp 18, resistance 23, lower inner armature and back contact of relay 15, lower outer armature and back contact ot' relay 20, armature and front contact ot' relay 16 to ground. The lighting of lamp 18 indicates to the B operator, at which position trunk 5 terminates, that a connection is desired over this trunk. The operation ot relay 17 completes connections to the sequence circuit 10, such as a connection from ground at its upper armature and front contactto lead 21 and a connection trom battery at its lower armature and back contact to lead 22.

A description ot this sequence circuit 10 will now be made. VIn case the o perators telephone set 100 isvnot connected at the time to any other engaged trunk it will be immediately connected to trunk The first operation towards accomplishing this will be the operation of relay over the following circuit, if it is assumed that trunk 5 is number one ot the trunks that may be connected to the ope'ators telephone set. Battery 35, winding of relay 257 conductor 21, lower' armature and back contact ot relay 19, upper armature and front contact of relay 17 to ground. The operation ot relay 25 closes an energizing circuit :tor relay 26 as follows: battery, winding oi' relay 26, armature and front` cont-act of relay 25, makebefore-break contacts of relays 25 and 25 to ground at 27. The operation ot relay 26 extends through the operation of its armatures, the tip and ring leads or' trunk 5 to the common leads 29 and 30, respectively. It also connects lead 22 to a common lead 81, lead 33 from lamp 18 to a common lead 34 and opens a connection from battery 35,

through its lower inner armature and bachr contact toeorresponding cont-acts of relay 2G and other intermediate relays (not shown) for other trunks, all for purposes as will hereinafter be described.

Theconnection of lead 33 to lead 34 coinpletes a circuit for relay 102 as follows: battery, winding of relay 102, lead 34, lead 33, resistance 23, lower inner armature and Vback contact olf relay 15, lower inner armature and back contact of relay 20, armature and it'ront contact ot' relay7 l0 to ground. This circuit causes the operation of relay 102 which in turn closes an obvious energizing circuit 'tor relay 104 which in energizing` close an obvious energizing circuit for relay 105. It should be noted that relays 101 and 105 are slow to operate so that an ap preciable time interval will elapse before relay 105 is operated after the operation of relay 102A ll hen relay 105 finally operates, a connection is made at its armature and iront contact directly to battery from lead 34. This connection shunts the connection from ground at relay 16 to the battery through lamp 18 and relay 102 so that lamp 18 will new become extinguished and relay 102 released. On the release ot relay 102, relays 1011 and 105 are in turn released. On the release of relay 105 the shunt to battery ior lead 34 is removed and lamp 18 is y again lighted, and relay 102 is again operated. The reoperation oi relay 102 causes the, ,repetition of the above cycle ot operations and release ot relays 104, 105, 102 and extinguishing of lamp 18, and consequently the closing of a connection between lead 33 and lead 34 will effect continued -flashing operations oi lamp 18. This lighting and extinguishing of lamp 18 at intervals indicates to the B operator that the telephone set 100 is connected to trunk 5, for it will be noted in the follmving description that simultaneously with the operations just described tor the flashing of lamp 18 the connection o1 the set 100 has actually taken place.

y On the connection ot lead 22 to lead 31, a circuit was completed t'or relay 107 as tollows: battery, lower armature and front contact o1 relay 17, upper winding of relay 1S), malte-betore-break contacts oit relay 19,

leads 22 and 31, armature and back contact oi relay 108, armature and back contact oi relay 109, winding of relay 107 to ground. This causes the operation o1E relay 1.07 which in turn closes an obvious energizing circuit. for relay 110. Relay 110 in operating completes a locking circuit ttor itself through its lower outer armature and trout contact to the make-betore-break contacts of relay 115 and alsol completes a connection :trom a tone source 120 through the primary winding oi repeat-ing coil 121, upper armature and back Contact of relay 111, upper middle arn1a- Ill (ill

4contact throi .r

turel and front Contact ot relay 110 to ground. Relay 110' also connects the secondarygo't the repeating coil 121 to the tip andinnerarniature and front Contact or relayQG,l

conductor 29, upper inner Varmature `and hack contact of relay 11G, upper outer arnia ture'arul front contacto'l relay 110, secondary winding ot repeating coil' 121, upper inner armature and front Contact ot relay 110, lower inner armature and hach' contact ot relay 11G, conductor 33th lower outer armature `and trout Contact ol. relay 26 and ring,` conductor ot trunk 'l' he operation of relay 110 there'lore through its connections v.signals serve as an indication to the A operator that the Il operators telephone eet 11)() is connected to a trunk The opera` tion of these relays to aeconfiplieh this purpose will now he de t, ihed. .lt will loe noted that on thel operation of` relay 1.1117 an obvious; circuit is completed 'For the operation ot relay 1.11,. The operation oit relay 111 opens the circuit through the primary winding' oit repeatingl coil lljlironi the tone source 121) so that when this relay operates, the tone is rcnioved 'troni the tip and ring condimtors ot trunk Relay 111 howeverrslow to operateso that the tone applied hy the operation of relay 1l() will he oit a lsutlicient duration to he heard hy the 11" operator. On the operation oi relay 111 an oln'ious circuit is closed 'i'or the slow-toA operate relay ,112. The operation ot relayV 112 agaix'i closes; a circuit through the primary windingr o1 repeating coil 121 from ierouml at its upper arnntture andiront Y i` the upper' varmature and. hack coi/itact o1" relay 113 so that when relay 112 operatesl a'liter a cerlain period a tone will he again applied to the tip and ring; coruluctore of trunk The operation ot relay 112 closes an ohrious energizing ircuit ilor the =,lo\vtooperale relay 113 so that lurl'ore relay 112:1 operatee` the tone will have heen transmittml to the i-Voperator Ai'or :i period ot time o'l2 the eanie length as the period ot the lirst application ol tone to the' All operattnf. The operation of relay 1151 closes an obvious energizingr circuit tor theV slow-tooperate relay 114 which now closes u circuit through the primary winding1 otl repeatingL coil 121,50 that a third application ottone is niade through the tip and ring conductors o't' trunk 5 andV heard bythe A operator. On the operation ot relay 114 an obvious energizing circuit is closed for the slowto-operate relay 115. The operation of relay 115 opens the locking circuit lor relay 11() previously traced hut relay 10T is still operated, relay llOlwill not release at this time. v The operation of relay 11:3 also `closes an obvious energizing circuit for relay 11G which in operating opens the connections from the secondary Windingot repeating coil 121 to` conductors 29 and 30 and trunk 1" and consequently upon the operation olf this relay, the third `and last application ot tone to the A operator is removed. The operation ot relay 11G now connects at its inner upper and lower ar1natures and front contacts the tip and ring' conductors of the operators telephone set to the conductors 29 and 3l), so that the connection from this operators telephone set is now completed to the tip and ring conductors ot trunk 5.

TiVhen the A operator receives the ahove mentioned signals4` she will understand thereby that the B operators telephone set is connected to trunk 5 and she will then transmit the number ot the wanted suhscriber to which the Blfoperator is to comof the A operator and the dashing ot lamp 18 take place practically simultaneously, the

E operator will be n'epared tor the reception oit the number oi the wanted sul'iscriliier as soon as the A operattnf ready to give it. .i

Before proceedingl lwith the description relating' to the completion ot the connection, a description ot` the tnnoliions ot thesequence circuit l() will now he made. In a case where the operatore telephone set 10() is connected to any engaged trunk other than trunk` at the time trunk becomes engaged and it is assumed that the 'trunk associated with rel l 25 and 2G theone with vwhich the oilieratoids telephone. set 10() engaged the Vcircuits will 'function ae tollows: On the engagement of 'trunk 5. relay 25 will operate*directly from vbattery but relay 213 will not become energized the circuit tor this relay to `ground at 27 is broken at the maltebetere-break contacte et relay so that a connection ot the operators telephone set 101') to trunk :'i cannot take place until it has heen disengaged from the trunk associated with relays 25 and 26 and not until the release of relay 25. 0n the other hund it, for example, the trunk associated with the relays 25 and Q6 is the one with which the operatol."s telephone set 100 is eng-raged at the time theltrunl; associated with relays 25 and 2G" becomes ill) loo

V2G will'he prevented trom operating due to the tact that the circuit for ythis relay will be broken at'the make-and-break contact oitu relay Another example mi ght be nientioned: In case the operators telephone set engaged. withA trunk and the trunk 'associated with relays 2G and 25 becomes engaged, the operators telephone set cannot be connected with this trunk as the circuit for relay 25 will be opened at the inner lower armature and back contact ot relay 2G lso that relay 25 cannot o )erate ,and close the circuit for relay QG. i' lso after the operators telephone set is connected to trunk 5 and the trunks associated with rela (S and .25 and Q6 and 25 become engaged while the operators set is still connected to trunk 5the trunk associated with relays :'Zt and 25 will be connected to the operator-s teephone set iirst. On the operation ot' relay y25 the circuit for relay 2G Ytrom ground at 2T will be opened.

Returning now to completion ol the connection to the wanted subscrbers line, the B operator having received the desired number from the A'loperator inserts plug 11 in jack 12 ot thewanted snbscribersl line 6. It plug 1l is inserted in 'jack 12 slowly so that the connection through the sleeve terminals are completed prior to the completion ot a. connection through the tip and ring terniinals a circuit will be completed as lollows: battery, windings ot relay 36 in series, inake-bet'ore-break contact` ot inarginal relay 37,A winding ot relay 3T, sleeve terminals ot plug 11 and jack l2 to ground. The electrical characteristics oil relay 3T' t #e such that it will not operate in this circuit, that is with the high and low resistance windings ot relay 36 in series-in the circuit. Relay 36, however, will'operate and a circuit will be closed ior relay as soon as the tip and ring terminals oi' plug 8 have made contact with the corresponding terminals ot jack 12. This circuit may be traced as tollows: lfrom one side ot battery. supplied at the line (whieh may be a sul'iseribei"s line or a trunk such as trunk 5 or any other well known type ot line having a battery connected to the tip andring conductors, over the ring conductor ot line (S, ring terminals of jack l2 and plug 11, upper armature and back Contact ot relay 37, winding of relay 38, armature and front contact ot relay 3G.

upper inner arn'iature and baci; contact ol relay 37, tip terminals of plug 11 and jack 12. over the tip conductor ot line (i to the ground at the opposite side ot the battery on line This circuit causes the operation oi relay 38 which now closes a short circuit to battery for the lower high resistance winding of relay The change in the elecytrical `character of the circuit through relay Y37 will now be such that this relay will operate. The operation ot relay 37 opens the circuit for relay 38 Vfrom the tip and ring conductors of line 6, causing relay'S to release. and this relay also opens the sleeve circuit to relay 36 and closes it through the lower armature and front contactot relay 37 to battery so as to maintain relay 37 energized. Relay 37 also completes the rng conductor from the ring terminal ot' plug l1 to trunk 5. Y

Another circuit is closed through the operation ot the lower armature ot relay 37 for the operation of relays 15 and ltlas follows: battery, lower armature and upper trout contact of relay 37, lower winding ot relay 19 to ground at. the make-beforebreak contacts ot relay 20 and a parallel branch from the battery at relay 37, winding ot relay 15 to ground at relay 20. The operation oit relay 15 now completes a circuit troni the tip conductor ot the trunk 5 through the upper' winding ot relay 16, upper inner armature and front Contact of reay l5, upper outer armature and front contact o't relay l5, tip terminal of plug 11 thus completing the tip conductor for the trunliaround the condenser 39. A similar connection is completed around condenser 40 from the ring conductor trunk 5 through the lower winding oliv relay 16, lower outer armature and front contact of relay l5 to the ring terminal of plug l1. It will be noted that only on the completion of the connection between the tip and ring terminals oi. plug 11 and corresponding terminals ole )ack 12 will relay 37 operate so as not to cause relay l5 to operate until the battery on line has actually been connected to the tip and ring conductors of trunk 5. The battery connection tor the incoming end ot trunk 5 will now, therefore, not be disturbed or broken by the operation ot relay l5 but will be immediately extended to the battery on line 6. 4

The provision oli relays 36 and 38 and the marginal operatingcharacteristics ot' relay 3? therefore prevent any 'false operation at the outgoing end of trunk 5 should the plug l1 not con'iplete theL connection between the tip and ring terminals to the battery onthe line 6 simultaneously with the closing ol the sleeve circuit on the insertion of 4the plug 11 into jack 12 ln ordinary circuits heretofore, it the tip and ring connection is not extended simultaneously with the sleeve connection, the ordinary relay corresponding to relay 3T might operate and cause the relay corresponding to relayl to operate before the connection to battery on a line such as 6 completed and thus cause an interruption ,in the battery supplied to the outgoing end of trunk 5. This provision is ot' particular importance in trunk connec lease.

tions where the battery supplied to 'thev out-` going end ot the trunk line pertorms some important functional; this end such as the holding ot certain rela-ys operated tor tno prevention ot prm'uatlu'o release ot the connection.

The operation ot reay ll) intentioned above causes the operator`s telwhone set 100 to be disconnected troni trunk hy opening the connection to battery for lead 22 at the 1nalie-be oi'e-ln'eah contacts oitl relay 19 and by opening the connection to ,ground lior lead 21 at the lower armature and back contact ot relay 1S). The removal ot' the ground from lead 21 causes relays 25 and 26 to be returned to normal. and the release ol'A relay 20 opens the connection -trom the common leads 9.0 and 30 to the trunk 5 and also opens the connection between lead 22 and lead 31 so that relay 107 will now re- On the release ot this relay the circuit lor relay 110 is opened and this relay :is in turn released. The release olf relay 110 causes in turn the release oil' relays 111, 112, 113, 114, 115 and 116 and when relay 11o releases the common conductors lll and 30 are disconnected from the operators tele phone set. 100.

.llt will be noted that on the release ot relay 112, a circuit is completed tor the pegcount meter 10las iliollows: Battery, windings` o'l peg-count meter 101` upper armature and 'front contact ot relay 115, malte-beitore-break contacts ot relay 1.12 to ground. is stated, the release ot relay 112 causes in succession the release ot relays 113, 11a, 115 and 11G so that when relays 113, 114.-, and 115 have released, the circuit .tor the meter is opened.

This circuit cannot airain be closed until. the operators telephone set 100 is connected with another trunk circuit, that until a cycle ol: operation sach as just described. 'for the relays 110 to 115 is again caused to take place dile to the operation oli relay 107. lt will. be noted that on the rel ase ot relay 107 a short circuit to ground is closed 'for leads 31 through the upper arn'iatrne and 'lront contacts ot relay 11G to `Q jround at the armature and back contact ot relay 107 so that relay 10T cannot again operate until relay 110 has released. This arrangement insures the completion ot one cycle ot operation of these relays to remove the operators telephone set 100 from the connnon leads .)rJ and B be'liore battery on lead 31 that may again be' connected thereto, in case another trunk has in the nieantinie beginn the operations i'or the association o'l the operatofs telephone set 100 with th: t trunk, will have any effect on the relays mentioned. In ac cordance with this` arranglelnent, there'lorc. the operation of the pea-count, meter 101 will not take place until the operator"s telephone set has been autonnitically disconnected from the trunk due to the insertion ol' Ythe plug 11 into jack 12. The meter 101 cannot therefore be vagain operated due to any accidental operations that may take place in a vtrunk connectionsuch as, for example, .il the plug' 11 is temporarily re` moved trom jack 12. The pegcount `meter i will register only once tor each connection established ,by a trunk in the ,group haring access to the operations telephone set loo. i

l'lelays 10o and 100 are provided in oon- `pinction with a key shown below relay 10'.)

to release the operatofs set 100 trom a trunk, it ior any reason the operator cannot complete a connection and the apparatus for automatically pert'orining this function is not brought into play or it it fails to 'itunetion. On depression ot the release key, relay 109 is operated and the connection loe tween lead 31 and relay 10T is broken, thus rel easing relay 107 with the result described. ronnd is then connected to both windings ot' relay 10S but as long as a battery con nection is maintained over lead 31, relay 10S does .not operate since one winding oppose:y the other. As soon as the battery connection to lead 3l is broken, relay 108 operates through its lower winding and this coiinection will be maintained as long,- as the release hey is depressed, thus preventing the olnyration olI the release key from being et- Ylective on more than one trunk for a single depression ot' the key. When the key is released, relays 10S and 109 release.

that is claimed is:

1. In a telephone system, a line, a connectingv trunk therefor, a relay arrangement for completinga talking` connection and maintrainings)` without interruption a certain electrical condition on said trunk,`means for operating said relay arrangement responsive to the connection oit all of the conductors oi the trunk with the corresponding conductors o1 the line. y Y

2. In a telephone system, a line, a connectine' trunk therefor. a relay in the sleeve circuit olf said trunk lor completing the talking conductors in said trunk, .means tor operat im;` said relay responsive to the complete connection ot all the conductors ol the trunk with the corresponding conductors of the line.

3. In a telephone system. a line having its tip and ring; conductors connected to ground and battery respectively, a connecting truuk therefor harina' the incomingy ends ot its tip andA ring` conductors connected respectively to around and battery, a relay arrangen'ient controlled through the sleeve circuit oi said trunk and responsive in one manner to the connection ot the sleeve conductor ot said trunk with the corresponding conductor ol. the line` a relay, a circuit therefor normally open and lnidpged across the tip and ring conductor ot the trunk, means ttor closing said bridge in response to the operation of the relay arrangement in the said one manner, means for operating said relay respon sive to the connection of the tip and rng conductors olf the trunk with lhecorresponding conductors of the line, :md means controlled by the operation of said relay to control said relay arrangement to operate vin another mannerso as to remove the ground and loattery connections from the tip and ring conductors of the trunk, and connect to said truuk the ground and battery connections of the line without interruption in the Supply of current through the trunk from said ground and buttery connections.

1n Witness whereof`r I hereunto subscribe my name this 7th day of August A. D., 1925.

CLARENCE B. FOVVLER. 

